Illumination device and liquid crystal display device

Abstract

An illumination device includes a light source and a planar illuminator for emitting light of the light source portion from one surface thereby to illuminate a liquid crystal panel. The planar illuminator has a reflection surface, on which minute concavo-convex shapes are substantially randomly formed. Surface emission is performed by diffuse reflecting the light irradiated from the light source portion by the reflection surface.

1. An illumination device, comprising:
 a light source; and 
 a planar illuminator for illuminating an illuminated object by emitting light of the light source from one surface, 
 wherein the planar illuminator has a reflection surface, on which minute concavo-convex shapes are substantially randomly formed, 
 wherein the light irradiated from the light source is diffusively reflected by the reflection surface thereby to perform surface emission, 
 wherein the light source is arranged at a side of the planar illuminator, and 
 wherein a reflection surface of the planar illuminator is a tilted surface that rises as the reflection surface becomes more distant from the light source. 
 
   
   
     2. The illumination device according to  claim 1 , wherein a prism-shaped prism sheet is disposed between the reflection surface of the planar illuminator and the illuminated object. 
   
   
     3. The illumination device according to  claim 2 , wherein the prism sheet controls the directivity of at least two light components, which travels in different directions in plan view. 
   
   
     4. The illumination device according to  claim 3 , wherein the prism sheet has a prism shape where a plurality of polypyramid-shaped or conical protrusions is formed. 
   
   
     5. The illumination device according to  claim 4 , wherein the vertical angle of the polypyramid-shaped or conical protrusion is in the range of 70° to 110°. 
   
   
     6. The illumination device according to  claim 4 , wherein a vertical angle of the polypyramid-shaped or conical protrusion is in the range of 80° to 100°. 
   
   
     7. The illumination device according to  claim 4 , wherein the protrusion has any one of a quadrangular pyramid, a hexangular pyramid, and an octangular pyramid shape. 
   
   
     8. The illumination device according to  claim 1 , wherein the light source is a cold cathode fluorescence lamp. 
   
   
     9. The illumination device according to  claim 1 , wherein the light source is an LED or an LED array. 
   
   
     10. The illumination device according to  claim 1 ,
 wherein the light source comprises a substantially rod-shaped light guider and a light emitting element disposed at an end of the longitudinal direction of the light guider, 
 wherein the light guider introduces light of the light emitting element from one end thereof to the inside thereof and emits the light to an emission surface disposed on one side, 
 wherein a side opposite to the emission surface of the light guider is curved, and 
 wherein a plurality of grooves extended to the peripheral direction of the light guider is formed along the curve. 
 
   
   
     11. The illumination device according to  claim 10 , wherein the pitches of the plurality of grooves formed in the light guider gradually become narrower from the side where the light emitting element is disposed and the depths of the grooves gradually become deeper. 
   
   
     12. A liquid crystal display device, wherein the illumination device according to  claim 1  is disposed in the rear side of the liquid crystal panel. 
   
   
     13. An illumination device, comprising:
 a light source; and 
 a planar illuminator for illuminating an illuminated object by emitting light of the light source from one surface, 
 wherein the planar illuminator has a reflection surface, on which minute concavo-convex shapes are substantially randomly formed, 
 wherein the light irradiated from the light source is diffusively reflected by the reflection surface thereby to perform surface emission, and 
 wherein a prism-shaped prism sheet is disposed between the reflection surface of the planar illuminator and the illuminated object. 
 
   
   
     14. The illumination device according to  claim 13 , wherein the prism sheet controls directivity of at least two light components, which travels in different directions in plan view. 
   
   
     15. The illumination device according to  claim 14 , wherein the prism sheet has a prism shape where a plurality of polypyramid-shaped or conical protrusions is formed. 
   
   
     16. The illumination device according to  claim 15 , wherein a vertical angle of the polypyramid-shaped or conical protrusion is in the range of 70° to 110°. 
   
   
     17. The illumination device according to  claim 15 , wherein a vertical angle of the polypyramid-shaped or conical protrusion is in the range of 80° to 100°. 
   
   
     18. The illumination device according to  claim 15 , wherein the protrusions have any one of a quadrangular pyramid, a hexangular pyramid, and an octangular pyramid shape. 
   
   
     19. The illumination device according to  claim 13 , wherein the light source is a cold cathode fluorescence lamp. 
   
   
     20. The illumination device according to  claim 13 , wherein the light source is an LED or an LED array. 
   
   
     21. The illumination device according to  claim 13 ,
 wherein the light source comprises a substantially rod-shaped light guider and a light emitting element disposed at an end of a longitudinal direction of the light guider, 
 wherein the light guider introduces light of the light emitting element from one end thereof to an inside thereof and emits the light to an emission surface disposed on one side, 
 wherein a side opposite to the emission surface of the light guider is curved, and 
 wherein a plurality of grooves extended to a peripheral direction of the light guider is formed along the curve. 
 
   
   
     22. The illumination device according to  claim 21 , wherein pitches of the plurality of grooves formed in the light guider gradually become narrower from a side where the light emitting element is disposed and depths of the grooves gradually become deeper. 
   
   
     23. A liquid crystal display device, wherein the illumination device according to  claim 13  is disposed in the rear side of the liquid crystal panel. 
   
   
     24. An illumination device, comprising:
 a light source; and 
 a planar illuminator for illuminating an illuminated object by emitting light of the light source from one surface, 
 wherein the planar illuminator has a reflection surface, on which minute concavo-convex shapes are substantially randomly formed, 
 wherein the light irradiated from the light source is diffusively reflected by the reflection surface thereby to perform surface emission, 
 wherein the light source comprises a substantially rod-shaped light guider and a light emitting element disposed at an end of a longitudinal direction of the light guider, 
 wherein the light guider introduces light of the light emitting element from one end thereof to an inside thereof and emits the light to an emission surface disposed on one side, 
 wherein a side opposite to the emission surface of the light guider is curved, and 
 wherein a plurality of grooves extended to a peripheral direction of the light guider is formed along the curve. 
 
   
   
     25. The illumination device according to  claim 24 , wherein pitches of the plurality of grooves formed in the light guider gradually become narrower from a side where the light emitting element is disposed and depths of the grooves gradually become deeper. 
   
   
     26. The illumination device according to  claim 24 , wherein a prism-shaped prism sheet is disposed between the reflection surface of the planar illuminator and the illuminated object and the prism sheet controls directivity of at least two light components, which travels in different directions in plan view. 
   
   
     27. The illumination device according to  claim 26 , wherein the prism sheet has a prism shape where a plurality of polypyramid-shaped or conical protrusions is formed. 
   
   
     28. The illumination device according to  claim 27 , wherein a vertical angle of the polypyramid-shaped or conical protrusion is in the range of 70° to 110°. 
   
   
     29. The illumination device according to  claim 27 , wherein a vertical angle of the polypyramid-shaped or conical protrusion is in the range of 80° to 100°. 
   
   
     30. The illumination device according to  claim 27 , wherein the protrusions have any one of a quadrangular pyramid, a hexangular pyramid, and an octangular pyramid shape. 
   
   
     31. The illumination device according to  claim 24 , wherein the light source is a cold cathode fluorescence lamp. 
   
   
     32. The illumination device according to  claim 24 , wherein the light source is an LED or an LED array. 
   
   
     33. A liquid crystal display device, wherein the illumination device according to  claim 24  is disposed in the rear side of the liquid crystal panel.